the speed of light either green red or what ever is constant for two stationary object (the source and the receiver) but when one body or the two are moving, you applied Doppler effect.

Maybe i should just give the answer, or wait some more?

(The man was initially booked for beating the lights and being drunk, but when he made that statement, they had to book him for overspeeding too!)

Further your career. Postgraduate studies in US and Canada. learn more here http://www.graduate-studies..com/

I'm happy 2 see a thread like this. I'm a Physics and Electronics graduate and I currently work as a Meteorologist. Most of the Meteorologist I know are either Physicist or Mathematician.

No one wants to give that problem a crack? Why is every1 quiet? Mod maybe u shld gv d soln since all 'em Physicists are scared.

sleekcm:

No one wants to give that problem a crack? Why is every1 quiet? Mod maybe u shld gv d soln since all 'em Physicists are scared.

Everyone is busy making money, i guess.

Was thinking i'd wait till December b4 giving the solution so it'd be the Question Of The Year.
[s]
Someone came very close to the answer though.[/s]

helo fellow physicist.i just got admitted into university of portharcourt 2 study physics,i want 2 no if i can b cleard wit agric in place of biology cos i got d7 in biology nd b3 in agric,pls in nid an urgent reply,tanks guys.

Final Attempt: Since our favourite drunk claimed he saw green as he approached d stop lights,we'll derive his f w.r.t c and wavelength {green}. F= 3 E 8%565nm. Now, his speed at this f, v= wavelength{g+r}*f= 1190nm*(3E8/565nm) = 6.318584*10^6 m/s. If that isn't d soln,sm1 shld school me pls.

sleekcm:

Final Attempt: Since our favourite drunk claimed he saw green as he approached d stop lights,we'll derive his f w.r.t c and wavelength {green}. F= 3 E 8%565nm. Now, his speed at this f, v= wavelength{g+r}*f= 1190nm*(3E8/565nm) = 6.318584*10^6 m/s. If that isn't d soln,sm1 shld school me pls.

Dec 31, 2012.

God willing.

yamakuza:

Dec 31, 2012.

God willing.

Time to burst your bubble

Red light has a wavelength of approximately 700 nm(which corresponds to a frequency of about 430 THz), while green light would be about 535 nm(frequency of 560 THz).

Doppler formula for the blueshift effect is:
f'=(c/(c+v)) * f, so we get:
v = c * ((f/f')-1)

v is radial speed from source to observer. Negative v indicates the velocity vector has to point towards source.

Calculating:
v = -0.232 c , which would be about 70000 km/s.

My source: http://wiki.answers.com/Q/How_fast_would_you_have_to_go_to_turn_a_red_light_green#ixzz1k6NMZg43

AjanleKoko:

Time to burst your bubble

Red light has a wavelength of approximately 700 nm(which corresponds to a frequency of about 430 THz), while green light would be about 535 nm(frequency of 560 THz).

Doppler formula for the blueshift effect is:
f'=(c/(c+v)) * f, so we get:
v = c * ((f/f')-1)

v is radial speed from source to observer. Negative v indicates the velocity vector has to point towards source.

Calculating:
v = -0.232 c , which would be about 70000 km/s.

My source: http://wiki.answers.com/Q/How_fast_would_you_have_to_go_to_turn_a_red_light_green#ixzz1k6NMZg43

Aaaaaaw!

Congratulations!

EEE (2) : PHY (0)

^^^
Physics grads fall hand again
[size=3pt]no thanks to Google and Wikipedia[/size]

To be honest, i saw that question many years ago and needed someone to rework it.

Sleekcm's answers were too preposterous so i immediately knew he was wrong.

Anyway, in trying to find the answer, i came across an alternative solution and would like our Esteemed Physicists to throw more light:

v = delta lambda c

(lamda2 - lambda1/lambda2) * c

gives 0.2c or 0.3c depending on your choice of lambda(1 or 2).

1. Which formula is this?

2. Which answer is more correct?

Thanks!

^^

http://en.wikipedia.org/wiki/Relativistic_Doppler_effect

AjanleKoko:

^^

http://en.wikipedia.org/wiki/Relativistic_Doppler_effect

Thanks!

This proves your initial answer wasnt just Google Effort.

So,

z = delta lambda c
   = 0.2c (blueshift?)
   = 0.3c (redshift?)

Caramba!

EEE (4) : PHY (0)

Aha! I'v bn properly schooled here. Gave it a shot anyways.

sleekcm:

Aha! I'v bn properly schooled here. Gave it a shot anyways.

Dont worry. Its the spirit that counts.

At least, its supposed to!

Pls

has @Ajanlekoko's riddle been solved,

yamakuza:



Anyway, in trying to find the answer, i came across an alternative solution and would like our Esteemed Physicists to throw more light:

According to one of my dumb lecturers then, He said BRING the LIGHT let ME THROW IT,

bukkytroni:

Pls

has @Ajanlekoko's riddle been solved,

The one about the gravity train? Yeah, some dude made a good attempt.
Just google 'Gravity Train' and you'll see the details of the solution.

I was wondering what happened to all the physicists. Apparently like t22, everyone of you guys have gone into IT and finance

AjanleKoko:

The one about the gravity train? Yeah, some dude made a good attempt.
Just google 'Gravity Train' and you'll see the details of the solution.

I was wondering what happened to all the physicists. Apparently like t22, everyone of you guys have gone into IT and finance

@Ajanlekoko

No be our fault o. Na Nigerian situation cause am. Physics is all about thinking, Who can think on hungry stomach, As long as there is money in return for the thinking, I can guarantee you, all the physics decampees will soon be back,

bukkytroni:

@Ajanlekoko

No be our fault o. Na Nigerian situation cause am. Physics is all about thinking, Who can think on hungry stomach, As long as there is money in return for the thinking, I can guarantee you, all the physics decampees will soon be back,

Money isn't everything bro.

AjanleKoko:

Money isn't everything bro.

it is. what is the point working 4 a peanut?

lekside44:

it is. what is the point working 4 a peanut?

Money certainly hasn't helped Nigeria or Nigerians.
My brother, I have been to many countries that are poor, even some under sanctions from UN. In their 'poverty',  when you see what the people are able to achieve, you will cry for yourself and your nation.

I find that Nigerians are always talking about money. Even the very intelligent Nigerians nowadays think and talk only about money. Just how much money do you need to live life?

At the beginning of your career, never work to earn. Work to learn.

can any physicist answer d question without cheating? why did NASA spend millions to develop a pen that could write in space when they could have just stick to using pencil?

Taiw:

can any physicist answer d question without cheating? why did NASA spend millions to develop a pen that could write in space when they could have just stick to using pencil?

*answer deleted*

waiting for The Physicists.

Taiw:

can any physicist answer d question without cheating? why did NASA spend millions to develop a pen that could write in space when they could have just stick to using pencil?

NASA spent millions to develop a pen that could write in space when they could have just stick to using pencil because of the following reasons:

1. the pencil leads, when broken ,float in the atmosphere where there is zero gravity;this constitutes a hazard to the eye and nose and could cause a short in an electric devices;

2.both the pencil lead and wood could burn rapidly in pure oxygen atmosphere .


In other words, they made safety priority taken a cue from what happened in the first Appollo (fire).

@ topic

The best option is probably to go for the masters and then phd, like others have said.

Physics, like maths, is a very good course but the challenge is little information about their applications and edge in the job market.

But these are fields the world simply cant do without because they're very important for technological advancement.

Taiw:

can any physicist answer d question without cheating? why did NASA spend millions to develop a pen that could write in space when they could have just stick to using pencil?

What constitutes cheating?

why did NASA spend millions to develop a pen that could write in space when they could have just stick to using pencil?

that seems to be an urban legend.



an explanation is on wiki and snopes:

A common urban legend states that, faced with the fact that ball-point pens will not write in zero-gravity, NASA spent a large amount of money to develop a pen that would write in the conditions experienced during spaceflight (the result purportedly being the Fisher Space Pen), while the Soviet Union took the simpler (and cheaper) route of just using pencils.

Russian cosmonauts used pencils, and grease pencils on plastic slates until also adopting a space pen in 1969 with a purchase of 100 units for use on all future missions.[1] NASA programs previously used pencils (for example a 1965 order of mechanical pencils[2]) but because of the substantial dangers that broken-off pencil tips and graphite dust pose in zero gravity to electronics and the flammable nature of the wood present in pencils[2] a better solution was needed. NASA never approached Paul Fisher to develop a pen, nor did Fisher receive any government funding for the pen's development. Fisher invented it independently, and then asked NASA to try it. After the introduction of the AG7 Space Pen, both the American and Soviet (later Russian) space agencies adopted it.

http://en.wikipedia.org/wiki/Space_Pen

^ Interesting answer by tpia there, caught by spambot.

[s]Seems to corroborate that of chukxy too.[/s]

^The "s.pambot" got it right after i typed it.

Couldnt be bothered reposting with another id (maybe some other time when i've dreamed up a really interesting moniker).

But if i should descend on whoever is sending that s.pambot after me though- dem go know wetin dem no know before.